stm32g0: add dma.

same same, bit for bit, except not ;) - Channel request mapping now
depends on a new DMAMUX peripheral, and there's no default preset.
So, before enabling dma channel after its configuration, request
must be configured by :

dmamux_set_dma_channel_request(DMAMUX1, DMA_CHANNELx, request_number_from_datasheet);

include/libopencm3/stm32/dma.h

@@ -38,6 +38,8 @@
 #       include <libopencm3/stm32/l1/dma.h>
 #elif defined(STM32L4)
 #       include <libopencm3/stm32/l4/dma.h>
+#elif defined(STM32G0)
+#       include <libopencm3/stm32/g0/dma.h>
 #else
 #       error "stm32 family not defined."
 #endif

include/libopencm3/stm32/g0/dma.h

@@ -0,0 +1,34 @@
+/** @defgroup dma_defines DMA Defines
+ *
+ * @ingroup STM32G0xx_defines
+ *
+ * @brief Defined Constants and Types for the STM32G0xx DMA Controller
+ *
+ * @version 1.0.0
+ *
+ * LGPL License Terms @ref lgpl_license
+ */
+
+/*
+ * This file is part of the libopencm3 project.
+ *
+ * This library is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef LIBOPENCM3_DMA_H
+#define LIBOPENCM3_DMA_H
+
+#include <libopencm3/stm32/common/dma_common_l1f013.h>
+
+#endif

lib/stm32/g0/Makefile

@@ -35,6 +35,7 @@ TGT_CFLAGS	+= $(STANDARD_FLAGS)
 ARFLAGS		= rcs
 
 OBJS += crc_common_all.o
+OBJS += dma_common_l1f013.o
 OBJS += exti.o exti_common_all.o
 OBJS += flash.o flash_common_all.o
 OBJS += gpio_common_all.o gpio_common_f0234.o